This invention relates to alloys for use in light water nuclear reactor (LWR) core structural components and fuel cladding. More particularly, this invention relates to a zirconium alloy for such use which exhibits superior corrosion resistance and mechanical properties after irradiation. Still more particularly, this invention relates to a zirconium alloy with improved corrosion resistance and mechanical properties by controlling its alloy composition to within particular ranges. Still more particularly, this invention relates to a zirconium alloy with controlled levels of tin (Sn), nitrogen (N), and niobium (Nb) additions to within specified limits, also suitable for pressurized water reactors (PWRS).